1. Field of the Invention
The present invention relates to a sealed case, and in particular to a sealed case comprising an elongated cylindrical trunk member with open end portions, a first cover member to close one open end portion of the trunk member, and a second cover member to close the other open end portion of the trunk member.
2. Description of the Related Art
Conventionally, a sealed case of the above-mentioned structure is made of a thick paper blank shaped as predetermined, for example. A blank is desirably as thin as possible to reduce the manufacturing cost of such a sealed case. However, use of a thin blank involves a rigidity problem, and limits the usage.